This invention relates to moisture separator reheaters for nuclear power plants and, in particular, to a moisture separator reheater having a heat exchanger comprising a plurality of U-shaped tubes. Such moisture separator reheaters are well known in the art and are typically used between a high-pressure steam turbine and a low-pressure steam turbine in a nuclear power plant. The U-shaped tubes are typically supported by immovable tube supports which sometimes cause the tubes to bind at the edges of the tube support apertures due to thermal expansion.